DB2 - Problem description
Problem IC67839 | Status: Closed |
REDISTRIBUTE ON MDC TABLES WITH MANY CELLS CRASHES OR PERFORMS SLOWLY | |
product: | |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 | |
Problem description: | |
During regular processing, the redistribute utility will create a number of control files (CF) to record progress about the current redistribute operation. These files allow redistribute to restart after a failure, and allow the user to CONTINUE or ABORT the operation. Redistribute on an MDC table can create too many of these control files and hit one of these problems: 1)Operating System being unable to handle the number of open files or 2) Insufficient space in the file system. 3) Slow redistribute performance due to REDISTRIBUTE keeping track of all the file handles on receiver partitions. This problem affects systems with MDC tables with many cells and a large number of sender partitions. During the redistribute of an MDC table, redistribute can generate a large number of 28 and 56 byte files in the redistribute control file directory. This scenario occurs when the redistribute utility is redistributing an MDC table, but no data from an MDC cell is leaving from a sender partition to a receiver partition. Each MDC cell in which there is no data being sent, will first result in an open CF of 28 bytes, many of these can be opened simultaneously, because there is no throttling mechanism. If too many are open, it can result in Operating System being unable to handle the number of files created. After redistribute processing on the receiver partitions, the CF will eventually be closed, and the CF of 56 bytes will stay until the end of the redistribute operation. Redistribute will fail to prune these unnecessary 56 byte CF files during processing. This can result in too much space being used in the redistribute control file directory where these files are stored. Due to REDISTRIBUTE having to keep track of these files we might hit one of the problems mentioned above. This problems affects a regular REDISTRIBUTE operation as well as a REDISTRIBUTE ABORT/CONTINUE. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Users with DPF * **************************************************************** * PROBLEM DESCRIPTION: * * Redistribute on an MDC table can create too many control * * files and hit this APAR. * **************************************************************** * RECOMMENDATION: * * Customer could abort the redistribute if it is slow and * * continue after the instance recycle. * * Recommend to apply fixpack 6 to resolve the issue. * **************************************************************** | |
Local Fix: | |
available fix packs: | |
DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows | |
Solution | |
This APAR is first fixed in Fixpack 6 | |
Workaround | |
not known / see Local fix | |
BUG-Tracking | |
forerunner : APAR is sysrouted TO one or more of the following: IC68070 IC68071 follow-up : | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 13.04.2010 09.09.2010 09.09.2010 |
Problem solved at the following versions (IBM BugInfos) | |
Problem solved according to the fixlist(s) of the following version(s) |